（ただし１と２を合せて１２のような使い方は出来ません。）
84個の解法が見つかりました。
((1×(2×5))÷1)=10
((1×1)×(2×5))=10
((1×2)×(1×5))=10
((1×2)×(5÷1))=10
((1×2)÷(1÷5))=10
((1×5)×(1×2))=10
((1×5)×(2÷1))=10
((1×5)÷(1÷2))=10
((1+(2×5))-1)=10
((1-1)+(2×5))=10
((1÷1)×(2×5))=10
((2×(1×5))÷1)=10
((2×(5÷1))÷1)=10
((2×5)×(1×1))=10
((2×5)×(1÷1))=10
((2×5)+(1-1))=10
((2×5)-(1-1))=10
((2×5)÷(1×1))=10
((2×5)÷(1÷1))=10
((2÷(1÷5))÷1)=10
((2÷1)×(1×5))=10
((2÷1)×(5÷1))=10
((2÷1)÷(1÷5))=10
((5×(1×2))÷1)=10
((5×(2÷1))÷1)=10
((5÷(1÷2))÷1)=10
((5÷1)×(1×2))=10
((5÷1)×(2÷1))=10
((5÷1)÷(1÷2))=10
(1×((2×5)÷1))=10
(1×(1×(2×5)))=10
(1×(2×(1×5)))=10
(1×(2×(5÷1)))=10
(1×(2÷(1÷5)))=10
(1×(5×(1×2)))=10
(1×(5×(2÷1)))=10
(1×(5÷(1÷2)))=10
(1+((2×5)-1))=10
(1-(1-(2×5)))=10
(1÷((1÷2)÷5))=10
(1÷((1÷5)÷2))=10
(1÷(1÷(2×5)))=10
(2×((1×5)÷1))=10
(2×((1+5)-1))=10
(2×((5÷1)÷1))=10
(2×(1×(1×5)))=10
(2×(1×(5÷1)))=10
(2×(1+(5-1)))=10
(2×(1-(1-5)))=10
(2×(1÷(1÷5)))=10
(2×(5×(1×1)))=10
(2×(5×(1÷1)))=10
(2×(5+(1-1)))=10
(2×(5-(1-1)))=10
(2×(5÷(1×1)))=10
(2×(5÷(1÷1)))=10
(2÷((1×1)÷5))=10
(2÷((1÷1)÷5))=10
(2÷((1÷5)÷1))=10
(2÷(1×(1÷5)))=10
(2÷(1÷(1×5)))=10
(2÷(1÷(5÷1)))=10
(5×((1×2)÷1))=10
(5×((1+2)-1))=10
(5×((2÷1)÷1))=10
(5×(1×(1×2)))=10
(5×(1×(2÷1)))=10
(5×(1+(2-1)))=10
(5×(1-(1-2)))=10
(5×(1÷(1÷2)))=10
(5×(2×(1×1)))=10
(5×(2×(1÷1)))=10
(5×(2+(1-1)))=10
(5×(2-(1-1)))=10
(5×(2÷(1×1)))=10
(5×(2÷(1÷1)))=10
(5÷((1×1)÷2))=10
(5÷((1÷1)÷2))=10
(5÷((1÷2)÷1))=10
(5÷(1×(1÷2)))=10
(5÷(1-(1÷2)))=10
(5÷(1÷(1×2)))=10
(5÷(1÷(2÷1)))=10